1. Field of the Invention
The present invention relates to a pivotal hinge (or pivotal device), and more particularly to a pivotal hinge (or pivotal device) with which a cover of a laptop computer or a mobile phone can be raised or lowered relative to a chassis of the laptop computer or the mobile phone.
2. Description of the Related Art
A conventional pivotal device is used for a laptop computer or a mobile phone and has a shaft. A first end of the shaft is connected to a seat which is securely mounted on a chassis of a laptop computer or a mobile phone and a second end of the shaft is connected to a base which is pivoted with a cover of the laptop computer or the mobile phone. The second end of the shaft is also pivotally connected to an adjusting element and a resistance element. Multiple resetting elements and washers are respectively mounted between the adjusting element and the resistance element. The adjusting element comprises a rotating member and a positioning member. When the rotating member is rotated relative to the positioning member, the cover of a laptop computer or a mobile phone can be lowered or raised relative to the chassis of the laptop computer or the mobile phone. When the rotating member is mated with the positioning member, the cover is positioned to the chassis with the friction force of the washers and resistance element.
However, the disadvantages of the conventional pivotal device are described as follows:
1. The conventional pivotal device has a complex structure thereby resulting in a high cost and inconvenient assembly.
2. Friction between the resistance element and the washers are not enough for the cover to be reliably positioned relative to the chassis.
Therefore, the invention provides a pivotal hinge to mitigate or obviate the aforementioned problems.